I'm not sure if this is why mine drink water, but whenever we come in from being outside, I tell them to go get some water. When they were little, they obviously did't understand so I would take them over to the bowl and if they didn't drink I would dip my fingers in the water and then rub it on their muzzle.
Each time we come in I tell them to drink water and the run right over to it. Even when we're playing and they start to pant, I will tell them and the go and drink.
It's too the point now that they just automatically go over and drink after coming in on a hot day. I would just say consistency would be the key. Good luck.
p.s. how about having several bowls of water available? Then gradually move them into the area that you want to wind up having them. I ddi this as well.
